Engine starter drive



Y. SEKELLA ENGINE STARTER DRIVE Filed Jan. 16, 1937 INVENTOR.

. ORNEY.

Patented May 24, 1938 UNITED ENGINE STARTER DRIVE tion of New York Application January 16, 1937, Serial No. 120,947

4 Claims.

The present invention relates to an engine starter drive and more particularly to that form of drive in which a motor-actuated pinion is automatically traversed into and out of engagement with a member of an engine to be started.

In those forms of starter drives known commercially as the barrel type drives, such as disclosed in the patents to McGrath 2,017,566 and Sekella 2,062,430, where the longitudinal movement of a nut on a screw shaft is limited by an abutment in the form of a stop nut, it has been found advantageous to retain the stop nut from unscrewing and pulling loose by riveting or staking it in place. While this method of fastening the stop nut has been found commercially efficacious, it has the disadvantage that removal of the stop nut for the purpose of disassembling and servicing the drive is rendered difficult without the use of special tools for that purpose.

It is an object of the present invention to provide a novel barrel type starter drive in which the parts are effectively locked in operative relation, but may readily be disassembled for inspection or service.

It is another object to provide such a device in which the drive spring and its associated parts may be disassembled without disassembling the barrel and stop nut.

It is a further object to provide such a device in which the spring and its associated parts may be assembled and removed from one end of the drive assembly while the barrel and its associated parts are assembled from the other end.

It is another object to provide such a device in which the anchoring means for the drive spring is positive in action but readily removable Without special tools.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. l is a side elevation partly broken away and in section of a preferred embodiment of the invention;

Fig. 2 is an end view thereof; and

Fig. 3 is a detail in perspective of the mounting sleeve and spring anchoring member partly broken away.

Referring first to Fig. l of the drawing, there is illustrated a power shaft l which may be the extended armature shaft of a starting motor, not illustrated. A mounting sleeve 2 is fixed on the power shaft as by means of a key 3 (Fig. 2) and pin #3 and is provided with a reduced smooth portion 5 on which is slidably journalled a screw shaft 6. Longitudinal movement of the screw shaft 6 on the sleeve 2 is limited in one direction by the shoulder l at the end of the reduced portion 5 thereof, and in the other direction by a stop nut 8 threaded on the end of the sleeve and securely retained thereon by staking or expanding portions 9 of the end of the sleeve into castellations ii in the end of the stop nut 8.

A pinion i2 is freely journalled on the power. shaft I and is connected by a barrel member l3 to a nut 84 threaded on the screw shaft 6, said nut being provided with lugs I5 extending radially into slots it in the barrel and being retained therein by means of a split lock ring i1.

Means are provided for yieldably connecting the screw shaft 6 to the sleeve 2 in the form of a torsion and compression spring it having outturned ends 19 and 2| engaging in slots in anchoring members in the form of discs 22 and 23 respectively non-rotatably connected to the screw shaft and sleeve as by means of non-circular openings in said anchoring discs conforming to non-circular portions of the screw shaft and sleeve (Fig. 3).

Longitudinal movement of the anchor member 22 on the screw shaft is limited by a shoulder 24 formed thereon, and longitudinal movement of the anchor member 23 on the sleeve under the expansive action of spring 18 is limited by a split lock ring 25 seating in a groove 26 in said sleeve and projecting therefrom, as best illustrated in Fig. 3, to form an abutment for the anchor member.

In the operation of the device, rotation of the power shaft I is transmitted through the sleeve 2, anchor member 23, spring l8, and anchor member 22 to the screw shaft 6, causing rotation thereof in unison with the power shaft. Acceleration of the screw shaft 6 causes the nut M to thread itself along the shaft into engagement with the stop nut 8, thus moving the pinion l2 longitudinally into engagement with a member, not illustrated, of an engine to be started. Longitudinal motion of the nut 14 being arrested, and rotation of pinion 42 being resisted by its engagement with the engine member, the screw shaft 6 is constrained to move back, compressing the spring I8 until stopped by the shoulder 'l on the sleeve, whereupon a yielding driving connection through the spring l8 to the pinion I2 is established for cranking the engine. When the engine starts, the overrunning action of the engine returns the pinion I2 and screw shaft 6 to their idle positions, as illustrated, in the usual manner.

A thrust washer 2! is preferably interposed between the shoulder I and the end of screw shaft 6.

It will be readily appreciated that by virtue of the removability of the lock ring 26 for the anchor member 23, said anchor member, the spring l8 and anchor member 22 may all be readily disassembled Without disturbing the stop nut 8 or removing the screw shaft 6. Since the barrel l3 ,and pinion I2 may also be disassembled upon removal of the lock ring I1, it will be seen that all these components of the drive may be removed for inspection or service without having to loosen the stop nut B.

Although but one form of the invention has been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the construction and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In a starter drive for internal combustion engines, a mounting sleeve, a hollow screw shaft slidably journalled thereon, said sleeve having a stop member fixed thereto for limiting the longitudinal movement of the screw shaft thereon, means for yieldably connecting the screw shaft to the sleeve including a compression and torsion spring, an anchor member connecting one end of the spring to the screw shaft, an anchor member for the other end of the spring slidably and non-rotatably mounted on the sleeve, a removable locking ring for the latter anchor member seated in said sleeve, and means for transmitting rotation from said screw shaft to a member of an engine to be started.

2. In a starter drive for internal combustion engines, a sleeve, a hollow shaft slidably journalled thereon, said sleeve having a stop member fixed thereto for limiting the longitudinal movement of the shaft thereon, means for yieldably connecting the shaft to the sleeve including a compression and torsion spring, an anchor member connecting one end of the spring to the shaft, an anchor member for the other end of the spring in the form of a disc having a noncircular bore slidably fitting a non-circular part of the sleeve, said sleeve having a peripheral groove, and a split lock ring seated in the groove confining the anchor member on the sleeve.

3. In an engine starter drive, a sub-assembly unit including a barrel member, a pinion fixed On one end thereof, a nut member non-rotatably mounted in the other end thereof, and a screw shaft on which said nut is threaded in combination with a yielding driving connection for the screw shaft including a sleeve carrying said screw shaft and having abutments limiting the travel of the screw shaft thereon, a coiled spring and slidable collars receiving and anchoring the ends of the spring to the sleeve and screw shaft respectively, and a split locking ring forming a removable abutment for the anchoring collar on the sleeve.

4. In an engine starter drive, a hollow drive shaft having a non-circular enlarged portion at one end forming an abutment shoulder, and a H stop member fixed to the other end, a screw shaft journalled on the drive shaft and longitudinally movable thereon between the shoulder and stop, said screw shaft having an enlarged non-circular portion at its end adjacent the corresponding portion of the drive shaft, anchor members slidably but non-rotatably mounted on the enlarged portions of the driving and screw-shafts, a torsion spring connecting said anchor members, said enlarged portion of the drive shaft having a peripheral groove, and an annular abutment member removably seated in said groove engaging the adjacent anchor member and thereby serving to retain the spring and anchor member assembly on the drive shaft.

YO-USTON SEKELLA. 

